5results about How to "Reduce resonance effect" patented technology

The present disclosure provides a piezoelectric self-feedback excitation type micro electric field sensor, an electric field detection method and a sensor, and is applied to the technical field of electric field sensors. The piezoelectric self-feedback excitation type micro electric field sensor comprises: a substrate for supporting a vibration pickup reference structure, a piezoelectric driving structure, a mutual shielding electric field sensing structure and an elastic beam; the piezoelectric driving structure is used for deforming the piezoelectric driving structure to make the elastic beam vibrate when a driving voltage is applied to the piezoelectric driving structure; the mutual shielding electric field sensing structure is used for outputting a differential form of a sensing current signal in response to the vibration of the elastic beam, so as to suppress common mode noise and detect the amplitude strength of the electric field to be measured; the vibration pickup reference structure is used for outputting a reference current signal in response to the vibration of the elastic beam, so as to adjust the size of the driving voltage, so that the output sensitivity of the piezoelectric self-feedback excitation type micro electric field sensor is a predetermined value.

The utility model discloses a low noise automobile tire belongs to automobile tire technical field, including tire body, longitudinal pattern groove, drainage pattern groove and first sound absorption pit, tire body tread is equipped with several longitudinal pattern grooves, several drainage pattern grooves are equipped in the tire body's shoulder position, and the first sound absorption pit is equipped on the inner wall of tire body, and several first sound absorption pits are evenly distributed along the circumferential inner wall of tire body. The prior art has solved the problem that the optimization effect is not obvious, the tire weight is increased and the production cost is improved due to the relatively limited space of pattern optimization and form adjustment and the addition of mute material. The utility model solves the three big problems of the noise reduction bottleneck, weight increase and cost increase of the traditional technology through structural innovation, and provides a technical solution with performance and economy for the electric automobile tire.

This invention discloses a low-odor, low-VOC gradient ultrafine polypropylene meltblown sound-absorbing and sound-insulating composite noise reduction material, belonging to the technical field of polymer noise reduction and environmentally friendly materials. This invention uses 1-5μm ultrafine PP meltblown fibers as the core substrate to construct a continuous gradient density sound-absorbing structure, achieving full-frequency sound wave gradient dissipation and attenuation. Modified activated carbon particles are embedded in situ within the meltblown fiber network, enabling efficient adsorption and purification of trace VOCs released from the substrate and environmental odor gases. A three-layer co-extruded barrier film of PE / PA / PE is composited with the outer side of the meltblown substrate to construct a constrained damping sound insulation system, significantly weakening the film resonance effect, improving the sound insulation trough, and greatly enhancing the material's low-frequency sound insulation performance. This effectively solves the industry's technical pain points of traditional PP meltblown noise reduction materials, such as high odor, high VOC content, fragmented sound absorption and insulation functions, narrow effective noise reduction frequency band, and poor composite structure stability. It can be widely applied in high-end noise reduction and environmental protection scenarios such as automotive interiors, building decoration, rail transit, and home appliances.

The application relates to a dynamic precision compensation control method based on an intelligent PCB drilling machine, which comprises the following steps: collecting a dynamic parameter set in real time through a multi-source sensor group installed on a drilling main shaft, the dynamic parameter set comprising displacement deviation caused by main shaft axial deformation, thermal deformation quantity analyzed based on interlayer temperature gradient, and frequency spectrum features reflecting tool-material coupling vibration, dynamically synthesizing a spatial trajectory correction instruction and a motion parameter optimization instruction according to the multi-dimensional compensation vector and current drilling process parameters, wherein the trajectory correction instruction is reconstructed through a B-spline curve to realize real-time interpolation of a path, a motion controller receives the spatial trajectory correction instruction and the motion parameter optimization instruction, at least three compensation iterations are completed in a single drilling cycle, a linear motor and a main shaft motor are driven to execute online precision compensation, and the compensation instruction execution delay is less than 2 ms.

The utility model discloses a kind of muffler air inlet pipe connecting frame, relate to agricultural machinery technical field.The muffler air inlet pipe connecting frame, including base, the base upper fixedly connected with engine, engine side surface fixedly installed with support frame, support frame is fixedly installed with shell, shell upper and lower sides are fixedly installed with air outlet pipe and air inlet pipe and with shell interior intercommunication, engine side surface is equipped with exhaust port, support frame lower side fixedly connected with pipe support, fixedly installed with rubber pad between pipe support and air inlet pipe;Support frame front end lower side fixedly installed with shock-absorbing rod.The muffler air inlet pipe connecting frame, the shock-absorbing spring of the muffler air inlet pipe connecting frame's connecting support frame installation can effectively attenuate low-frequency vibration generated when engine operates, through elastic deformation absorption vibration energy, reduce the vibration transmission caused by rigid connection, avoid the problem that weld point cracks, component loosening etc.